Production of ²³⁰Pa as a Source for Medical Radionuclides ²³⁰U and ²²⁶Th Including Isolation by Liquid–liquid Extraction

ABSTRACT

Liquid–liquid extraction of protactinium with different extractants (1-octanol, MIBK, aliquat 336) was studied depending on concentration of nitric and hydrochloric acids, presence of bulk amount of thorium, fluoride ions, and addition of boric acid or Al³⁺ ions as a masking agent. The extraction with 1-octanol followed by back-extraction with 7 M HCl + 0.1 M HF solution proved to be appropriate for selective ²³⁰Pa isolation from thorium irradiated with medium-energy protons. The proposed procedure provided simultaneous production of medical ²²⁵Ac and ²³⁰Pa/²³⁰U from the same Th-target. The experimental cross-sections of ²³⁰Pa formation in the reaction ²³²Th(p,3n)²³⁰Pa were determined for the protons energy range of 140–35 MeV and compared with literature data. The yield of ²³⁰U and impurities of ²³²U and ²³³U depending on the energy of protons entering a thick thorium target were estimated.

KEYWORDS:

• ²³⁰Pa
• ²³⁰U
• proton irradiation
• thorium target
• protactinium isolation
• Liquid–liquid extraction

Acknowledgments

This work was funded by the Russian Foundation for Basic Research, project number 20-53-15007.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Supplementary material

Supplemental data for this article can be accessed online at https://doi.org/10.1080/07366299.2022.2088059